Ok, so i've had this problem before and I had to reinstall XP to get it back to normal...basically, it happened without warning. I turned on the PC and when the BIOS screen came up which checks the hardware, it checked that the hardware was there and....just hung...it takes forever to boot up XP. Even going to the boot menu or startup menu in BIOS takes forever (about 15 minutes). Eventually, XP boots up and there is no problem. I've cleaned the register, cleared out all start-up programs and defragmented the hard drive to no avail. What could be causing the problem?